Status registration of packet routing nodes

ABSTRACT

A solution for establishing a data traffic session for a user equipment (UE) on a network (e.g., a 4G or 5G cellular network) includes: receiving, by a session management node, from the UE, a request to set up the data traffic session; establishing the data traffic session with a first packet routing node; receiving, by the session management node, from a network repository or the first packet routing node, an indication of unavailability of the first packet routing node to handle UE data traffic; and based on at least a status of the first packet routing node changing from available to handle UE data traffic to unavailable to handle UE data traffic, moving the data traffic session to the available alternate packet routing node.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of and claims priority toU.S. patent application Ser. No. 17/096,633, entitled “STATUSREGISTRATION OF PACKET ROUTING NODES,” filed on Nov. 12, 2020, thedisclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

After a packet routing node registers with a network repository, asession management node is able to assign the packet routing node tohandle data traffic between a user equipment (UE, cellular device) and apacket data network (PDN, e.g., a portion of the internet). The UE usesthe PDN to reaches a network resource node. However, if the packetrouting node becomes unavailable, or is otherwise unable to properlyhandle the UE's data traffic, the session management node may yetcontinue to assign the packet routing node to other UEs, resulting indelays and degraded experiences for those other UEs. In fifth generation(5G) cellular networks, the packet routing node may include a user planefunction (UPF); the network repository may include a network functionrepository function (NRF); and the session management node may include asession management function (SMF) node. In fourth generation (4G)cellular networks, the packet routing node may include a packet datanetwork gateway (PGW, or a PGW user plane function, PGW-U); the networkrepository may include a domain name system (DNS) server; and thesession management node may include a PGW control plane function(PGW-C).

SUMMARY

The following summary is provided to illustrate examples disclosedherein, but is not meant to limit all examples to any particularconfiguration or sequence of operations.

A solution for establishing a data traffic session for a user equipment(UE) on a network (e.g., a fifth generation (5G) cellular network orfourth generation (4G) cellular network) includes: receiving, by asession management node, from the UE, a request to set up the datatraffic session; establishing the data traffic session with a firstpacket routing node; receiving, by the session management node, from anetwork repository or the first packet routing node, an indication ofunavailability of the first packet routing node to handle UE datatraffic; and based on at least a status of the first packet routing nodechanging from available to handle UE data traffic to unavailable tohandle UE data traffic, moving the data traffic session to the availablealternate packet routing node. In 5G, the packet routing node mayinclude a user plane function (UPF); the network repository may includea network function repository function (NRF); and the session managementnode may include a session management function (SMF) node. In 4G, thepacket routing node may include a packet data network gateway (PGW, or aPGW user plane function, PGW-U); the network repository may include adomain name system (DNS) server; and the session management node mayinclude a PGW control plane function (PGW-C). In some examples, thenetwork resource node is reached via a packet data network (PDN), forexample, a portion of the internet.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed examples are described below with reference to theaccompanying drawing figures listed below, wherein:

FIG. 1A illustrates an exemplary arrangement that may advantageouslyestablish a data traffic session for a user equipment (UE) on a network,using status registration of packet routing nodes;

FIG. 1B illustrates an alternative exemplary arrangement that mayadvantageously establish a data traffic session for a UE on a network,using status registration of packet routing nodes;

FIG. 2 illustrates a messaging sequence that may be used within thearrangement of FIG. 1;

FIG. 3 illustrates a flow chart of exemplary operations associated withthe arrangements of FIGS. 1A and 1B;

FIG. 4 illustrates another flow chart of exemplary operations associatedwith the arrangements of FIGS. 1A and 1B; and

FIG. 5 illustrates a block diagram of a computing device that may beused as a component of the arrangements illustrated in FIGS. 1A and 1B.

Corresponding reference characters indicate corresponding partsthroughout the drawings. References made throughout this disclosure.relating to specific examples, are provided for illustrative purposes,and are not meant to limit all implementations or to be interpreted asexcluding the existence of additional implementations that alsoincorporate the recited features.

DETAILED DESCRIPTION

A solution for establishing a data traffic session for a user equipment(UE) on a network (e.g., a fifth generation (5G) cellular network orfourth generation (4G) cellular network) includes: receiving, by asession management node, from the UE, a request to set up the datatraffic session; determining, by the session management node, anavailability (reaching an acceptable performance threshold) orunavailability (not reaching an acceptable performance threshold) of afirst packet routing node to handle UE data traffic, wherein determiningthe availability or unavailability of the first packet routing node tohandle UE data traffic comprises receiving an indication of theavailability or unavailability of the first packet routing node from anetwork repository; based on at least on determining that the firstpacket routing node is available to handle UE data traffic, establishingthe data traffic session with the first packet routing node; and basedon at least on determining that the first packet routing node isunavailable to handle UE data traffic, establishing the data trafficsession with an available alternate packet routing node. In 5G, thepacket routing node may include a user plane function (UPF); the networkrepository may include a network function repository function (NRF); andthe session management node may include a session management function(SMF) node. In 4G, the packet routing node may include a packet datanetwork gateway (PGW, or a PGW user plane function, PGW-U); the networkrepository may include a domain name system (DNS) server; and thesession management node may include a PGW control plane function(PGW-C). In some examples, a network resource node (e.g., the endpointof the data traffic session) is reached via a packet data network (PDN),for example, a portion of the internet.

Aspects of the disclosure improve the speed and reliability of cellulardata sessions by determining, by a session management node, anavailability or unavailability of a first packet routing node to handleUE data traffic, and based on at least on determining that the firstpacket routing node is unavailable to handle UE data traffic,establishing the data traffic session with an available alternate packetrouting node. This prevents wasting timeout periods attempting toestablishing the data traffic session with the first packet routingnode.

The packet routing node detects the performance of its interface withthe PDN (e.g., an N6 interface, for 5G) and its registration status witha network repository indicates the status to the session managementnode. This way, the session management node is provided with timelystatus of the packet routing node's ability to handle UE data traffic.In some examples, the packet routing node also pushes its status thesession management node, for example, if the packet routing node detectsthat the performance of its interface with the PDN has deteriorated orits service health has otherwise deteriorated.

In some examples, the packet routing node will register itself with thenetwork repository only if it is available to handle UE data traffic,but de-register itself with the network repository when it becomesunavailable to handle UE data traffic. This way the availability orunavailability of the packet routing node may be determined by whetherit is registered at all. In some examples, the packet routing node willregister itself with the network repository using a flag to indicatewhether it is available to handle UE data traffic or unavailable tohandle UE data traffic. In such examples, the availability orunavailability of the packet routing node may be determined by the flagassociated with its registration.

With reference now to the figures, FIG. 1A illustrates an exemplaryarrangement 100 a that may advantageously establish a data trafficsession 106 for a UE 102 on a network 110, using status registration ofpacket routing nodes 130 a, 130 b, and 130 c (together, a plurality ofpacket routing nodes 130). Network 110 may be a fifth generation (5G)cellular network, or another type of network. FIG. 1B illustrates anexemplary arrangement 100 b in which components of network 110 arerepresented as a fourth generation (4G) cellular network, although withoperations and components otherwise corresponding with those ofarrangement 100 a.

A UE 102 is attempting to set up data traffic session 106 in order toreach a network resource node 142 across a PDN 140. Network resourcenode 142 may be, for example, a data source located in the internet. UE102 will be able to reach network resource node 142 using an airinterface 114 with RAN 112, then through a packet routing node (which isto be determined) that is in communication with PDN 140. In 5G, each ofpacket routing nodes 130 a, 130 b, and 130 c includes a UPF; RAN 112communicates with a UPF (packet routing node) via an N3 interface; and aUPF communicates with PDN 140 via an N6 interface. Although additionaldetail is shown for packet routing node 130 a, it should be understoodthat packet routing node 130 b and packet routing node 130 c may besimilarly configured.

When setting up data traffic session 106, UE 102 sends a request to asession management node 120, via RAN 112 and an access node 122. Sessionmanagement node 120 queries a policy node 124 to determine whether therequest is permitted and, if so, queries a network repository 126 todiscover packet routing nodes (e.g., packet routing nodes 130 a, 130 b,and 130 c) to assign to UE 102 for handling data traffic session 106. In5G, access node 122 includes an access and mobility management function(AMF) node; session management node 120 includes an SMF node; policynode 124 includes a policy charging function (PCF) node; and networkrepository 126 includes an NRF. Also in 5G, UE 102 and RAN 112communicate with access node 122 via an N1 and/or an N2 interface;access node 122 communicates with session management node 120 via an N11interface; and session management node 120 communicates with policy node124 via an N7 interface. Session management node 120 also communicateswith each of packet routing nodes 130 a, 130 b, and 130 c via an N4interface.

As disclosed herein, session management node 120 selects one of packetrouting nodes 130 a, 130 b, and 130 c to assign to UE 102 for handlingdata traffic session 106, based on availability. This sets up a defaultevolved packet system (EPS) bearer between UE 102 and PDN 140, with theselected packet routing node providing a point of exit and entry ofexternal packet data traffic for the UE (e.g., external to network 110).There exist multiple ways that a packet routing node may becomeunavailable. There may be a transport failure, such as the N6 interfacefails, and PDN 140 becomes non-responsive to the packet routing node,even if the N6 interface is still functioning properly.

FIG. 1B illustrates an alternative exemplary arrangement 100 b that mayadvantageously establish data traffic session 106 for UE 102 on anetwork 110 b, using status registration of packet routing nodes 130 a,130 b, and 130 c. Network 110 b may be a 4G cellular network, or anothertype of network. In 4G, each of packet routing nodes 130 a, 130 b, and130 c includes a PGW; access node 122 includes a Mobility ManagementEntity (MME) node; session management node 120 includes a servinggateway (SGW) and/or a PGW-C; access node 122 includes a policy andcharging rules function (PCRF) node; and network repository 126 includesa DNS server. Also in 4G, session management node 120 communicates witha PGW via an S5 (home network) or S8 (roaming) interface; and a PGWcommunicates with PDN 140 via an SGi interface. In 4G, there may not bedirect communication between a PGW and a DNS server.

Further description of FIGS. 1A and 1B will be made with additionalreference to FIGS. 2 and 3. FIG. 2 is a messaging sequence diagram 200that shows a series of messages may be used within arrangement 100 aand/or arrangement 100 b, and is described in conjunction with FIG. 3.FIG. 3 illustrates a flow chart 300 of exemplary operations associatedwith initiating a network session for UE 102 on network 110, and themessages of messaging sequence diagram 200 occur during variousoperations of flow chart 300. In some examples, at least a portion ofmessaging sequence diagram 200 and at least a portion of flow chart 300may each be performed using one or more computing devices 500 of FIG. 5.FIGS. 1A-3 should be viewed together.

Operation 302 (FIG. 3) includes monitoring a service performance betweenpacket routing node 130 a (a first packet routing node) and PDN 140.This is an ongoing operation, and is performed using message 202 a. Forexample, any or all of a ping test, uplink and/or downlink flowstatistics, and border gateway protocol (BGP) peer status may be used.In some examples, packet routing node 130 a comprises a UPF node. Insome examples, packet routing node 130 a comprises a PGW. In someexamples, a UPF node communicates with PDN 140 using an N6 interface. Insome examples, packet routing node 130 a comprises a PGW user planefunction (PGW-U) node. In some examples, a PGW communicates with PDN 140using an SGi interface. In some examples, PDN 140 comprises at least aportion of a public internet.

Also included in operation 302 is monitoring a service performancebetween packet routing node 130 b (a second packet routing node thatprovides an alternate packet routing node to packet routing node 130 a)and PDN 140; and monitoring a service performance between packet routingnode 130 c (yet another alternate packet routing node) and PDN 140.These operations are also ongoing, and use messages 202 b and 202 c,respectively. Operation 302 uses a tester 132 that collects results 134for the performance of packet routing node 130 a.

Operation 304 includes based on at least the service performance betweenpacket routing node 130 a and PDN 140 meeting performance threshold 136,indicating, by packet routing node 130 a, to network repository 126, theavailability or unavailability of packet routing node 130 a to handle UEdata traffic. In some examples, a reporter 138 compares results 134 withperformance threshold 136, and makes a binary determination of availableor unavailable. In some examples, reporter 138 does not make a binarydetermination, but instead provides a descriptive version of results 134to network repository 126, which appear as packet routing node 1 (PR1)availability flag 129 a in PR1 registration 128 a. Similarly, equivalentreporters in 5G packet routing nodes 130 b and 130 c may reportdescriptive testing results to network repository 126, which appear aspacket routing node 2 (PR2) availability flag 129 b in PR2 registration128 b, and as packet routing node 3 (PR3) availability flag 129 c in PR3registration 128 c, respectively. Descriptive testing results mayinclude latency, throughput (bandwidth), and/or bit error rate (BER). In4G, a DNS server may obtains corresponding information from PGWsindirectly.

In some examples, indicating the availability or unavailability ofpacket routing node 130 a to handle UE data traffic comprises, based atleast on packet routing node 130 a being available to handle UE datatraffic, registering packet routing node 130 a with network repository126. In such examples, reporter 138 only registers packet routing node130 a with network repository 126 if packet routing node 130 a isavailable to handle UE data traffic (e.g., results 134 meet performancethreshold 136), but does not register packet routing node 130 a withnetwork repository 126 if packet routing node 130 a is unavailable tohandle UE data traffic. In such examples, indicating the availability orunavailability of packet routing node 130 a to handle UE data trafficcomprises, based at least on packet routing node 130 a being unavailableto handle UE data traffic, de-registering packet routing node 130 a withnetwork repository 126, if packet routing node 130 a had been previouslyregistered.

In some examples, indicating the availability or unavailability ofpacket routing node 130 a to handle UE data traffic comprises, based atleast on packet routing node 130 a being available to handle UE datatraffic, registering packet routing node 130 a with network repository126 with PR1 availability flag 129 a. In such examples, indicating theavailability or unavailability of packet routing node 130 a to handle UEdata traffic comprises, based at least on packet routing node 130 abeing unavailable to handle UE data traffic, registering packet routingnode 130 a with network repository 126 with PR1 availability flag 129 a.Thus, in some examples, reporter 138 registers packet routing node 130 awith network repository 126 whether packet routing node 130 a isavailable or unavailable, and indicates availability or unavailabilityusing PR1 availability flag 129 a. In some examples, PR1 availabilityflag 129 a is binary, although in some examples, PR1 availability flag129 a may be descriptive (so that session management makes adetermination whether to use packet routing node 130 a using thedescription in PR1 availability flag 129 a).

The registration of packet routing node 130 a appears within networkrepository 126 as PR1 registration 128 a, and may include PR1availability flag 129 a (as described above). Similarly, theregistrations of packet routing nodes 130 b and 130 c may be similar.For example, the registration of packet routing node 130 b appearswithin network repository 126 as PR2 registration 128 b, and may includePR2 availability flag 129 b, and the registration of packet routing node130 c appears within network repository 126 as PR3 registration 128 c,and may include PR3 availability flag 129 c. For example, operation 304includes, based on at least the service performance between packetrouting node 130 b and PDN 140 meeting its performance threshold(equivalent to performance threshold 136), indicating, by packet routingnode 130 b, to network repository 126, the availability orunavailability of packet routing node 130 b to handle UE data traffic.The registrations, which may include descriptions of performance, areaccomplished using registration messages 204 a, 204 b, and 204 c. Insome examples, network repository 126 comprises an NRF node. In someexamples, network repository 126 comprises a DNS server.

UE sends a session request 206 to session management node 120, in orderto initiate data traffic session 106, in operation 306. Operation 306thus includes receiving, by session management node 120, from UE 102, arequest to set up data traffic session 106. In some examples, sessionmanagement node 120 comprises an SMF node. In some examples, sessionmanagement node 120 comprises a PGW-C node and/or a serving gateway(SGW). In some examples, an SGW communicates with a PGW using an S5/S8interface. In some examples, receiving, by session management node 120,from UE 102, the request to set up data traffic session 106 comprisesreceiving the request through access node 122. In some examples, accessnode 122 comprises an AMF node. In some examples, access node 122comprises an MME node.

In operation 308 session management node 120 queries network repository126 with a resource discovery message 208, and network repository 126responds with a message 210 that includes any of PR1 registration 128 a,PR1 availability flag 129 a, PR2 registration 128 b, PR2 availabilityflag 129 b, PR3 registration 128 c, and PR3 availability flag 129 c thatit has in its current registration data. Since the registrationsidentify the corresponding packet routing nodes, in some examples,operation 308 includes receiving, by session management node 120, fromnetwork repository 126, identification of packet routing node 130 a,packet routing node 130 b, and packet routing node 130 c. Any of PR1registration 128 a, PR1 availability flag 129 a, PR2 registration 128 b,PR2 availability flag 129 b, PR3 registration 128 c, and PR3availability flag 129 c that session management node 120 receives fromnetwork repository 126 is stored as packet routing node status 150.

In decision operation 310 (shown as selection 212 in FIG. 2) sessionmanagement node 120 uses determination logic 154 to determine (fromstatus 150) whether to assign packet routing node 130 a or packetrouting node 130 b or UE 102. Decision operation 310 thus includesdetermining, by session management node 120, an availability orunavailability of packet routing node 130 a to handle UE data traffic.In some examples, determining the availability or unavailability ofpacket routing node 130 a to handle UE data traffic comprises receivingan indication of the availability or unavailability of packet routingnode 130 a from network repository 126. Based on the determination ofwhether packet routing node 130 a is available, selection logic 156selects packet routing node 130 a or packet routing node 130 b (ifpacket routing node 130 b is available, as determined by determinationlogic 154. In some scenarios, if determination logic 154 determines thatpacket routing node 130 a and packet routing node 130 b are bothunavailable, but packet routing node 130 c is available, selection logic156 will select packet routing node 130 c. In some examples,determination logic 154 uses the presence or absence of a registrationof a packet routing node; in some examples, determination logic 154 usesa binary flag within a registration of a packet routing node; and someexamples, determination logic 154 uses a descriptive flag within aregistration of a packet routing node.

If packet routing node 130 a is unavailable to handle UE data traffic(but packet routing node 130 b is available), session management node120 will use packet routing node 130 b for data traffic session, asshown in operation 312. Operation 312 includes based on at least ondetermining that packet routing node 130 a is unavailable to handle UEdata traffic, establishing data traffic session 106 with packet routingnode 130 b (an available alternate packet routing node). In this case,subsequent operations 314-328 are performed as described below, butsubstituting packet routing node 130 b for packet routing node 130 a,and with packet routing node 130 a or packet routing node 130 c beingthe alternate packet routing node.

If packet routing node 130 a is available, operation 314 includes, basedon at least on determining that packet routing node 130 a is availableto handle UE data traffic, establishing data traffic session 106 withpacket routing node 130 a. This includes session management node 120sending message 216 to UE 102 and message 214 to packet routing node 130a. Data traffic session 106 then enters a first phase in which itincludes segment 106 a between UE 102 and packet routing node 130 a, andsegment 106 b between packet routing node 130 a and PDN 140.

However, it is possible that the performance of that packet routing node130 a may degrade, for one of the reasons described above. Thus, in someexamples, operation 316 includes repeatedly polling, by sessionmanagement node 120, network repository 126 to determine whether thestatus of packet routing node 130 a (or any other packet routing node)is changed from available to handle UE data traffic to unavailable tohandle UE data traffic. This is shown as message 218. Along with this,packet routing nodes 130 a, 130 b, and 130 c each continues monitoringits service performance with PDN 140. As indicated in FIG. 2, message202 b and message 202 c provide successful testing results, so thatpacket routing nodes 130 b and 130 c retain their registrations withnetwork repository 126. In some examples, registration message 204 b andregistration message 204 c are unnecessary, if packet routing nodes 130b and 130 c had already been registered. In some examples, registrationmessages 204 b and 204 c update descriptive performance data (e.g.,latency, throughput, BER) for packet routing nodes 130 b and 130 c. Insome examples, ongoing registration messages are used as a heartbeatsignal and if network repository 126 detects a missing registrationmessage after a timeout period, it updates the registration informationto indicate that the corresponding packet routing node is unavailable.

As shown for packet routing node 130 a, monitoring has failed. After atimeout period, packet routing node 130 a determines that it has becomeunavailable at 318 (shown as unavailability determination 220 in FIG.2). Operation 320 includes based on at least a status of packet routingnode 130 a changing from available to handle UE data traffic tounavailable to handle UE data traffic, indicating, by packet routingnode 130 a, to network repository 126, the unavailability of packetrouting node 130 a to handle UE data traffic. In some examples, packetrouting node 130 a deregisters with network repository 126 using message222. In such examples, indicating the availability or unavailability ofpacket routing node 130 a to handle UE data traffic comprises, based atleast on packet routing node 130 a being unavailable to handle UE datatraffic, de-registering packet routing node 130 a with networkrepository 126. In some examples, packet routing node 130 a maintainsits registration (e.g., PR1 registration 128 a remains at networkrepository 126), but updates PR1 availability flag 129 a within PR1registration 128 a.

In some examples, network repository 126 pushes an alert 224 to sessionmanagement node 120. Operation 322 includes, based on at least a statusof packet routing node 130 a changing from available to handle UE datatraffic to unavailable to handle UE data traffic, indicating, by networkrepository 126, to session management node 120, the unavailability ofpacket routing node 130 a to handle UE data traffic. In some examples,packet routing node 130 a pushes its own alert 226 to session managementnode 120. Operation 324 includes, based on at least a status of packetrouting node 130 a changing from available to handle UE data traffic tounavailable to handle UE data traffic, indicating, by packet routingnode 130 a, to session management node 120, the unavailability of packetrouting node 130 a to handle UE data traffic. In some examples (5G), aUPF node communicates with session management node 120 using an N4interface.

Session management node 120 selects an alternate packet routing node,such as packet routing node 130 b in operation 326 (shown as selection228 in FIG. 2). Operation 328 includes based on at least the status ofpacket routing node 130 a changing from available to handle UE datatraffic to unavailable to handle UE data traffic, moving data trafficsession 106 to packet routing node 130 b. This includes sessionmanagement node 120 sending message 232 to UE 102 and message 230 topacket routing node 130 a. Data traffic session 106 then enters anotherphase in which it includes segment 106 c between UE 102 and packetrouting node 130 b, and segment 106 d between packet routing node 130 band PDN 140. Session management node 120 also moves other UEs that hadbeen using packet routing node 130 a, as indicated within its assignmentlist 152. When later session requests arrive from other UEs, sessionmanagement node 120 will not assign packet routing node 130 a untilafter packet routing node 130 a has initiated its availability again onnetwork repository 126.

FIG. 4 illustrates a flow chart 400 of exemplary operations associatedwith establishing a data traffic session for a UE on a network. In someexamples, at least a portion of flow chart 400 may be performed usingone or more computing devices 500 of FIG. 5. Operation 402 includesreceiving, by a session management node, from the UE, a request to setup the data traffic session. Operation 404 includes determining, by thesession management node, an availability or unavailability of a firstpacket routing node to handle UE data traffic, wherein determining theavailability or unavailability of the first packet routing node tohandle UE data traffic comprises receiving an indication of theavailability or unavailability of the first packet routing node from anetwork repository. Operation 406 includes, based on at least ondetermining that the first packet routing node is available to handle UEdata traffic, establishing the data traffic session with the firstpacket routing node. Operation 408 includes, based on at least ondetermining that the first packet routing node is unavailable to handleUE data traffic, establishing the data traffic session with an availablealternate packet routing node.

FIG. 5 illustrates a block diagram of computing device 500 that may beused as a component of arrangement 100 a of FIG. 1A and/or arrangement100 b of FIG. 1B, for example, as any component described herein thatmay require computational or storage capacity. Computing device 500 hasat least a processor 502 and a memory 504 that holds program code 510,data area 520, and other logic and storage 530. Memory 504 is any deviceallowing information, such as computer executable instructions and/orother data, to be stored and retrieved. For example, memory 504 mayinclude one or more random access memory (RAM) modules, flash memorymodules, hard disks, solid-state disks, persistent memory devices,and/or optical disks. Program code 510 comprises computer executableinstructions and computer executable components including anyinstructions necessary to perform operations described herein. Data area520 holds any data necessary to perform operations described herein.Memory 504 also includes other logic and storage 530 that performs orfacilitates other functions disclosed herein or otherwise required ofcomputing device 500. An input/output (I/O) component 540 facilitatesreceiving input from users and other devices and generating displays forusers and outputs for other devices. A network interface 550 permitscommunication over a network 560 with a remote node 570, which mayrepresent another implementation of computing device 500. For example, aremote node 570 may represent another of the above-noted nodes withinarrangement 100.

ADDITIONAL EXAMPLES

An exemplary system for establishing a data traffic session for a UE ona network comprises: a processor; and a computer-readable medium storinginstructions that are operative upon execution by the processor to:receive, by a session management node, from the UE, a request to set upthe data traffic session; determine, by the session management node, anavailability or unavailability of a first packet routing node to handleUE data traffic, wherein determining the availability or unavailabilityof the first packet routing node to handle UE data traffic comprisesreceiving an indication of the availability or unavailability of thefirst packet routing node from a network repository; based on at leaston determining that the first packet routing node is available to handleUE data traffic, establish the data traffic session with the firstpacket routing node; and based on at least on determining that the firstpacket routing node is unavailable to handle UE data traffic, establishthe data traffic session with an available alternate packet routingnode.

An exemplary method of establishing a data traffic session for a UE on anetwork comprises: receiving, by a session management node, from the UE,a request to set up the data traffic session; determining, by thesession management node, an availability or unavailability of a firstpacket routing node to handle UE data traffic, wherein determining theavailability or unavailability of the first packet routing node tohandle UE data traffic comprises receiving an indication of theavailability or unavailability of the first packet routing node from anetwork repository; based on at least on determining that the firstpacket routing node is available to handle UE data traffic, establishingthe data traffic session with the first packet routing node; and basedon at least on determining that the first packet routing node isunavailable to handle UE data traffic, establishing the data trafficsession with an available alternate packet routing node.

One or more exemplary computer storage devices has computer-executableinstructions stored thereon, which, upon execution by a computer, causethe computer to perform operations comprising: receiving, by a sessionmanagement node, from a UE, a request to set up a data traffic session;determining, by the session management node, an availability orunavailability of a first packet routing node to handle UE data traffic,wherein determining the availability or unavailability of the firstpacket routing node to handle UE data traffic comprises receiving anindication of the availability or unavailability of the first packetrouting node from a network repository; based on at least on determiningthat the first packet routing node is available to handle UE datatraffic, establishing the data traffic session with the first packetrouting node; and based on at least on determining that the first packetrouting node is unavailable to handle UE data traffic, establishing thedata traffic session with an available alternate packet routing node.

Alternatively, or in addition to the other examples described herein,examples include any combination of the following:

-   -   based on at least a status of the first packet routing node        changing from available to handle UE data traffic to unavailable        to handle UE data traffic, moving the data traffic session to        the available alternate packet routing node;    -   monitoring a service performance between the first packet        routing node and a PDN;    -   based on at least the service performance between the first        packet routing node and the PDN meeting a performance threshold,        indicating, by the first packet routing node, to the network        repository, the availability or unavailability of the first        packet routing node to handle UE data traffic;    -   indicating the availability or unavailability of the first        packet routing node to handle UE data traffic comprises, based        at least on the first packet routing node being available to        handle UE data traffic, registering the first packet routing        node with the network repository;    -   indicating the availability or unavailability of the first        packet routing node to handle UE data traffic comprises, based        at least on the first packet routing node being available to        handle UE data traffic, registering the first packet routing        node with the network repository with an availability flag;    -   indicating the availability or unavailability of the first        packet routing node to handle UE data traffic comprises, based        at least on the first packet routing node being unavailable to        handle UE data traffic, de-registering the first packet routing        node with the network repository;    -   indicating the availability or unavailability of the first        packet routing node to handle UE data traffic comprises, based        at least on the first packet routing node being unavailable to        handle UE data traffic, registering the first packet routing        node with the network repository with an unavailability flag;    -   based on at least a status of the first packet routing node        changing from available to handle UE data traffic to unavailable        to handle UE data traffic, indicating, by the first packet        routing node, to the network repository, the unavailability of        the first packet routing node to handle UE data traffic;    -   based on at least a status of the first packet routing node        changing from available to handle UE data traffic to unavailable        to handle UE data traffic, indicating, by the first packet        routing node, to the session management node, the unavailability        of the first packet routing node to handle UE data traffic;    -   the first packet routing node comprises a UPF node;    -   the network repository comprises an NRF node;    -   the session management node comprises an SMF node;    -   a UPF node communicates with the PDN using an N6 interface;    -   the first packet routing node comprises a PGW;    -   the first packet routing node comprises a PGW-U node;    -   the network repository comprises a DNS server;    -   the session management node comprises a PGW-C node;    -   the session management node comprises an SGW;    -   a PGW communicates with the PDN using an SGi interface;    -   the PDN comprises at least a portion of a public internet;    -   a UPF node communicates with the SMF using an N4 interface;    -   a SGW communicates with a PGW using an S5/S8 interface;    -   receiving, by the session management node, from the UE, the        request to set up the data traffic session comprises receiving        the request through an access node;    -   the access node comprises an AMF node;    -   the access node comprises an MME node;    -   receiving, by the session management node, from the network        repository, identification of the available alternate packet        routing node;    -   based on at least a status of the first packet routing node        changing from available to handle UE data traffic to unavailable        to handle UE data traffic, indicating, by the network        repository, to the session management node, the unavailability        of the first packet routing node to handle UE data traffic; and    -   repeatedly polling, by the session management node, the network        repository to determine whether the status of the first packet        routing node is changed from available to handle UE data traffic        to unavailable to handle UE data traffic.

The order of execution or performance of the operations in examples ofthe disclosure illustrated and described herein is not essential, unlessotherwise specified. That is, the operations may be performed in anyorder, unless otherwise specified, and examples of the disclosure mayinclude additional or fewer operations than those disclosed herein. Forexample, it is contemplated that executing or performing a particularoperation before, contemporaneously with, or after another operation iswithin the scope of aspects of the disclosure. It will be understoodthat the benefits and advantages described above may relate to oneembodiment or may relate to several embodiments. When introducingelements of aspects of the disclosure or the examples thereof, thearticles “a,” “an,” “the,” and “said” are intended to mean that thereare one or more of the elements. The terms “comprising,” “including,”and “having” are intended to be inclusive and mean that there may beadditional elements other than the listed elements. The term “exemplary”is intended to mean “an example of.”

Having described aspects of the disclosure in detail, it will beapparent that modifications and variations are possible withoutdeparting from the scope of aspects of the disclosure as defined in theappended claims. As various changes may be made in the aboveconstructions, products, and methods without departing from the scope ofaspects of the disclosure, it is intended that all matter contained inthe above description and shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

What is claimed is:
 1. A method of establishing a data traffic sessionfor a user equipment (UE) on a network, the method comprising:receiving, by a session management node, from the UE, a request to setup the data traffic session; establishing the data traffic session witha first packet routing node; receiving, by the session management node,from a network repository or the first packet routing node, anindication of unavailability of the first packet routing node to handleUE data traffic; and based on at least a status of the first packetrouting node changing from available to handle UE data traffic tounavailable to handle UE data traffic, moving the data traffic sessionto an available first alternate packet routing node.
 2. The method ofclaim 1, wherein the indication of unavailability of the first packetrouting node to handle UE data traffic is received from the networkrepository.
 3. The method of claim 1, wherein the indication ofunavailability of the first packet routing node to handle UE datatraffic is received from the first packet routing node.
 4. The method ofclaim 1, further comprising: monitoring a service performance betweenthe first alternate packet routing node and a packet data network (PDN);and based on at least the service performance between the firstalternate packet routing node and the PDN meeting a performancethreshold, indicating, by the first alternate packet routing node, tothe network repository, the availability or unavailability of the firstalternate packet routing node to handle UE data traffic.
 5. The methodof claim 4, wherein indicating the availability or unavailability of thefirst alternate packet routing node to handle UE data traffic comprises:based at least on the first alternate packet routing node beingavailable to handle UE data traffic: registering the alternate firstpacket routing node with the network repository, or registering thefirst alternate packet routing node with the network repository with anavailability flag; and based at least on the first alternate packetrouting node being unavailable to handle UE data traffic: de-registeringthe first alternate packet routing node with the network repository, orregistering the first alternate packet routing node with the networkrepository with an unavailability flag.
 6. The method of claim 1,wherein the first alternate packet routing node comprises a user planefunction (UPF) node; wherein the network repository comprises a networkfunction repository function (NRF) node; wherein the session managementnode comprises a session management function (SMF) node; and wherein theUPF communicates with a packet data network (PDN) using an N6 interface.7. The method of claim 1, wherein the first alternate packet routingnode comprises a packet data network gateway (PGW) node or a PGW userplane function (PGW-U) node; wherein the network repository comprises adomain name system (DNS) server; wherein the session management nodecomprises a PGW control plane function (PGW-C) node or a serving gateway(SGW); and wherein the PGW communicates with a packet data network (PDN)using an SGi interface.
 8. A system for establishing a data trafficsession for a user equipment (UE) on a network, the system comprising: aprocessor; and a computer-readable medium storing instructions that areoperative upon execution by the processor to: receive, by a sessionmanagement node, from the UE, a request to set up the data trafficsession; establish the data traffic session with a first packet routingnode; receive, by the session management node, from a network repositoryor the first packet routing node, an indication of unavailability of thefirst packet routing node to handle UE data traffic; and based on atleast a status of the first packet routing node changing from availableto handle UE data traffic to unavailable to handle UE data traffic, movethe data traffic session to an available first alternate packet routingnode.
 9. The system of claim 8, wherein the indication of unavailabilityof the first packet routing node to handle UE data traffic is receivedfrom the network repository.
 10. The system of claim 8, wherein theindication of unavailability of the first packet routing node to handleUE data traffic is received from the first packet routing node.
 11. Thesystem of claim 8, wherein the operations are further operative to:monitor a service performance between the first alternate packet routingnode and a packet data network (PDN); and based on at least the serviceperformance between the first alternate packet routing node and the PDNmeeting a performance threshold, indicate, by the first alternate packetrouting node, to the network repository, the availability orunavailability of the first alternate packet routing node to handle UEdata traffic.
 12. The system of claim 11, wherein indicating theavailability or unavailability of the first alternate packet routingnode to handle UE data traffic comprises: based at least on the firstalternate packet routing node being available to handle UE data traffic:registering the alternate first packet routing node with the networkrepository, or registering the first alternate packet routing node withthe network repository with an availability flag; and based at least onthe first alternate packet routing node being unavailable to handle UEdata traffic: de-registering the first alternate packet routing nodewith the network repository, or registering the first alternate packetrouting node with the network repository with an unavailability flag.13. The system of claim 8, wherein the first alternate packet routingnode comprises a user plane function (UPF) node; wherein the networkrepository comprises a network function repository function (NRF) node;wherein the session management node comprises a session managementfunction (SMF) node; and wherein the UPF communicates with a packet datanetwork (PDN) using an N6 interface.
 14. The system of claim 8, whereinthe first alternate packet routing node comprises a packet data networkgateway (PGW) node or a PGW user plane function (PGW-U) node; whereinthe network repository comprises a domain name system (DNS) server;wherein the session management node comprises a PGW control planefunction (PGW-C) node or a serving gateway (SGW); and wherein the PGWcommunicates with a packet data network (PDN) using an SGi interface.15. One or more computer storage devices having computer-executableinstructions stored thereon, which, upon execution by a computer, causethe computer to perform operations comprising: receiving, by a sessionmanagement node, from a UE, a request to set up a data traffic session;establishing the data traffic session with a first packet routing node;receiving, by the session management node, from a network repository orthe first packet routing node, an indication of unavailability of thefirst packet routing node to handle UE data traffic; and based on atleast a status of the first packet routing node changing from availableto handle UE data traffic to unavailable to handle UE data traffic,moving the data traffic session to an available first alternate packetrouting node.
 16. The one or more computer storage devices of claim 15,wherein the indication of unavailability of the first packet routingnode to handle UE data traffic is received from the network repository.17. The one or more computer storage devices of claim 15, wherein theindication of unavailability of the first packet routing node to handleUE data traffic is received from the first packet routing node.
 18. Theone or more computer storage devices of claim 15, wherein the operationsfurther comprise: monitoring a service performance between the firstalternate packet routing node and a packet data network (PDN); and basedon at least the service performance between the first alternate packetrouting node and the PDN meeting a performance threshold, indicating, bythe first alternate packet routing node, to the network repository, theavailability or unavailability of the first alternate packet routingnode to handle UE data traffic.
 19. The one or more computer storagedevices of claim 18, wherein indicating the availability orunavailability of the first alternate packet routing node to handle UEdata traffic comprises: based at least on the first alternate packetrouting node being available to handle UE data traffic: registering thealternate first packet routing node with the network repository, orregistering the first alternate packet routing node with the networkrepository with an availability flag; and based at least on the firstalternate packet routing node being unavailable to handle UE datatraffic: de-registering the first alternate packet routing node with thenetwork repository, or registering the first alternate packet routingnode with the network repository with an unavailability flag.
 20. Theone or more computer storage devices of claim 15, wherein the firstalternate packet routing node comprises a user plane function (UPF)node; wherein the network repository comprises a network functionrepository function (NRF) node; wherein the session management nodecomprises a session management function (SMF) node; wherein the UPFcommunicates with a packet data network (PDN) using an N6 interface;wherein the first alternate packet routing node comprises a packet datanetwork gateway (PGW) node or a PGW user plane function (PGW-U) node;wherein the network repository comprises a domain name system (DNS)server; wherein the session management node comprises a PGW controlplane function (PGW-C) node or a serving gateway (SGW); and wherein thePGW communicates with a packet data network (PDN) using an SGiinterface.